Health Points

Health Points (HP) are the measure of vitality in Terraria. NPCs, monsters, and players all have Health Points. A newly spawned player will have 100 Health Points, or 5 hearts. However, Life Crystals, once found underground and used, provide the player with an extra heart permanently (20 Health Points) to a maximum of 400 Health Points or 20 hearts. The final heart, or the current one healing, will pulse back and forth. Life Fruits can also be used to increase your health by 5 Health Points permanently.

Damage is calculated using the formula "Damage = BaseDamage - (Defense/2)". Meaning, if you have 100 hp and take 20 damage while having 10 defense, the damage will be subtracted by your defense divided by 2, which in this case is 10/2=5, so the total damage dealt is 20-5 which is 15, causing your hp will now be 85.

Damage can't be fully negated. In any case players will take 1 damage (excluding fall damage that can be negated with various ways) that will be slowly regenerated if player has a Band of Regeneration equipped or the Buff "Regeneration" active (these can come from various sources such as Heart Lanterns, Campfires, or a Regeneration Potion)

Falling

Fall damage is dealt for every block fallen after the first 25. Base fall damage is 10 per block, but the player's defense reduces that amount. Drop height is determined from block of origin to destination block. Jumping will increase fall damage, even more so if you use a Shiny Red Balloon or Rocket Boots.

To prevent fall damage, the player can use a Grappling Hook, a Dual Hook, the Ivy Whip, the Cloud in a Bottle, or the Rocket Boots shortly before hitting the ground. Wearing Angel Wings or Demon Wings or any other set of wings will completely negate fall damage even when not actively gliding, as will the Lucky Horseshoe or Obsidian Horseshoe ; this removal of possible error makes them more efficient than the other tools. Falling into cobwebs or sufficiently-deep water will also prevent damage. Minimal requirements for preventing fall damage in water is one and a half blocks in height, and width has to be at least two blocks (enough for the character to fall into).

In earlier versions of the game Cloud in a Bottle only reduced damage taken when falling slightly, but didn't fully negate damage from major drops that the player endures. As of 1.0.4 this has been corrected. If you time your second jump correctly, you don't take any damage. This is because the Cloud in a Bottle as well as other double jumping items reset your character's velocity and thus the game thinks the player is falling at the height you double jumped at (explains why if you double jump at the wrong moment, you will die or still take damage)

Dying

If the Hit Points (HP) of a player or Monster reach 0, the player or Monster will die.

Dying will also set the Player's current HP to 100 no matter what their max HP is. Dying from explosives, however, will cause the player to receive full HP after respawning. Players do not lose money if they are killed by another player. This is to prevent griefing or players being hunted for their coins.

Healing

A player can recover HP by getting/using Small hearts, Life Crystals, Healing Potions, Restoration Potions, Mushrooms, Bottled Water, Bottled Honey, or life-stealing items such as Vampire Knives and any magic damage done with Spectre Armor. HP will also recover slowly on its own after not having been damaged for a while. The longer it has been since you've been hit, the faster your character regains health. If you move your character while the health points are being regenerated, the health rate will be slowed down to half. But if your character remains motionless, the health rate will be increased greatly. If you are hit during regeneration, or combat starts, the regeneration stops until the combat is done.

TIP: It is not required to put healing items in your hot-bar; patch PC 1.0.5 added an option for a healing item hotkey (default "H"). When pressed, this hotkey causes the player to use the first healing object in order from left to right and top to bottom.

If a player is standing next to a Heart lantern and a campfire, has drank a Regeneration Potion, and is/was recently standing in honey (within 30 seconds), they can regenerate slightly more than 10 Health per second. With a band of regeneration and Crimson Armor set, they can regenrate slightly more. With self-healing items (Vampire Knives), the player can infinitetly regenerate health at a rate in which they can be considered invincible.

A player can also "heal" their mana, by drinking mana potions (which have no cool down) or obtaining mana stars which drop from various sources.

Nurse

The Nurse NPC will only move into a suitable home (A suitable home consists of 1 Table, A chair, A light source, walls, a ceiling, a door, and at least one block for the NPC to stand on.) once your maximum Health Points have been increased by at least 1 heart crystal, and will heal you for a number of copper coins (75% the amount of health you need, and price is always rounded down. EX: 120 max health, 20 current. 100 healed = 75 copper, etc..). If a debuff is applied while you are being healed, each debuff will cost an addition 7 silver 50 copper. Example being: On Fire! and Potion Sickness= 15 silver additional. Although the Nurse removes Potion Sickenss debuff icon, the debuff is not removed until the timer is counted down. A current bug as of v1.2.1 is that the Campfire and Water Candle buff icons count toward the debuff to remove.

Max health

A player's maximum Health Points can be increased by 20 by consuming one Life Crystal (Obtained by smashing a Crystal Heart), up to a maximum of 400 health. You will need a total of 15 Life Crystals in order to reach max health, giving you 300 health plus the 100 HP you start off with as a new character. As of 1.2, the Life Fruit item (found in Hard ModeJungle) allows 500 maximum health points (if the player has reached 400 HP), since using one will permanently increase your maximum HP by 5. Lifeforce Potion was added in 1.2.4, and this allows a player's HP to reach 600 for the duration of

A player that reached 500 HP by using Life Fruits

5 minutes.

Health Changes

Health changes for both the player and enemies are represented by the floating numbers after a hit. Orange numbers represent damage done to an enemy, bold faced and slightly darker orange represent a critical hit, red numbers represent damage to players, and green numbers show recovered health. Blue numbers are not health related, but instead pertain to mana recovery.

Visual Bugs

When hovering over an Monster and depleting the health bar past its max health, the bar says their health is negative for 1 frame(tested on the Wall of Flesh).